Enlarged negs with APHS

[pwitkop]

I finally had a chance to start experimenting with enlarged negs (I got to the interposative step anyway) this afternoon. I got (what I think is) a decent posative, very full highlight details, and very flat by exposing a 35mm neg to 5x7 with an exposure of 25 sec. at f/22, and processing in pyrocat-hd 1:1:400. I souped one sheet at a time with 800ml of solution, I figured 2ml of a and b should be enough for one sheet anyway, used one shot. How much capacity could I expect out of such a high dilution? Could I get several sheets out of this much solution? I went that high to keep times long enough for me to be conistent, I'm looking at 6 min. with this setup.

Another thing I noticed was my fix (tf-4) seemed to exaust very quickly, after the first few sheets the fix was a pale yellow, and a drop of hyp-check showed it to be very exausted. I changed it with more (used) fix and the same thing happened after one sheet. I'd used this bottle of fix for a number of rolls of film, so it could easily have been nearly exausted when I started. Is there something interesting happening here or did I just have nearly exasted fix to start with?

Peter

 

[Akki14]

APHS seems to suck up fix and makes it go yellow quickly. Not sure why as it clears so fast. People at the local photo shop didn't understand why I wanted 5litre of rapid fix... between that and my 800ml for each 4x5 sheet using my paterson tank, it seems to go fast.

 

[davido]

yellow fix

It's been always my understanding that lith film turned fixer yellow and that didn't mean the fix is exhausted. when I've tested my fixer with hypo check it comes out fine.
Not sure if this has anything at all to do with this phenomenon, but I always pre-soak the film in a waterbath for 4 minutes to clear the anti-halation backing. it's also supposed to help the film develop more consistently.
I would be very interested to know why the fixer yellows so much. I believe that it's a sulphur precipitate.

-david

 

[pwitkop]

I pre-soaked my film as well, I wonder if the yellow is analogus to the type of dyes that make some pan films (like t-max) turn the fix pink. When I put a couple of drops of edwal hypo-check in, I got the white stuff, which as I understand it would only mean silver saturation. As I mentioned earlier, my fix had been used bit perviously, so even assuming aphs is hard on fix, it was probably close to capacity when I started. Tomorrow I'll make an acctuall negative, keep fingers crossed!

Peter

 

[Akki14]

I presoak (or briefly dip in water) and what comes off is nearly black/green in colour - not the yellow that drips off the sheet into the fix so I'm not sure what's going on there. It's fun stuff to work with. I've decided recently that using the enlarger with the lens opened up all the way gives me better contrast with brief 1-3second exposures but that's probably just me being weird... What are you intending to use the enlarged negatives for? pt/pd, cyanotype, normal silver contact printing?

 

[pwitkop]

I'm doing cyanotypes right now, or beginning to. I'd like to do a few images as tea/coffee toned cyanotypes, and learn to make enlarged negatives to eventually learn carbon printing. Today my first neg came out ok, these where 12" exposures developed in p-cat 1:1:100 for 5 min, 30 sec. We'll see how it goes when I get some more time to print them and work with them.

Peter